@vinu Ah, you'll want to pass an actual uid into the _uid query parameter, not a user token. I think that's the issue here.
Solved invalid csrf token
My installation has been working generally well for quite a while, but now all of a sudden, I generally can't post anything. The screen says "Forbidden" and the log says "invalid csrf token", which is also what it says when I try to log out. Stopping and restarting nodebb didn't clear it up. Any suggestions?
The problem went away when I cleared my cookies.